You need a Medallion Signature Guarantee any time the legal ownership of securities changes hands or the title on a securities account is altered. That covers selling or gifting stock certificates, transferring assets after a death, retitling holdings into a trust, adding or removing a joint owner, changing your name on an account, and replacing a lost or destroyed stock certificate. The guarantee is a special stamp from a bank, credit union, or brokerage firm that certifies your signature is genuine and that you have the authority to make the transaction, and the institution providing it takes on financial liability if either turns out to be false.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities That liability is why transfer agents trust it, and why a simple notary stamp will not do.
Transferring or Selling Securities
This is the situation that drives most requests. If you hold physical stock certificates and want to sell or give them to someone else, the transfer agent handling the transaction will not process the request without a guaranteed signature on the certificates or on the accompanying stock power form.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities The same rule applies when you move assets from one brokerage firm to another and the move itself involves a change in legal ownership, such as shifting shares out of your individual account and into a jointly held account at a different firm.
If a guarantee is missing or the stamp comes from an institution the transfer agent does not accept, the request is rejected and the transaction stalls. For high-value holdings, that delay can be expensive.
Settling a Deceased Owner’s Securities
When a securities owner dies, transferring the assets to beneficiaries, heirs, or an estate account requires a medallion guarantee on the transfer paperwork. The guarantee confirms that the person signing has legal authority to act on behalf of the estate, and transfer agents will not release the assets without it even when the instructions look straightforward.
In practice, the executor or personal representative has to bring court appointment documents along with the transfer forms. A will by itself is not enough. Most institutions want letters testamentary dated within the last 60 to 90 days, or, for smaller estates, a small estate affidavit. The affidavit route lets heirs collect assets without going through full probate, but the medallion guarantee on the transfer documents is still required. Gather everything before your appointment; showing up short of a document often means weeks of delay before heirs see anything.
Changing the Name or Owners on an Account
Even if you are not selling or giving away a single share, you will need a medallion guarantee whenever the legal title on an account changes. A name change after marriage or divorce is a common example. The transfer agent needs to be certain the person requesting the update is the same person who originally held the account, because falsified name-change paperwork is a known vector for identity theft.
Adding or removing a joint owner falls into the same category. Expanding or shrinking who holds legal title is functionally a partial transfer of ownership, so the transfer agent applies the same standard. If a divorce decree requires splitting a brokerage account, expect to need a guarantee on the paperwork that carries out the split.
Retitling Securities Into a Trust
Funding a trust with securities you already own is one of the most common estate planning steps that triggers this requirement. You are changing the legal title from yourself as an individual to the trust as a separate legal entity, which transfer agents treat as a formal change of ownership. You complete assignment forms or a stock power, sign them, and have the signature guaranteed. This holds for both revocable and irrevocable trusts.
Skip the guarantee and the trust may remain unfunded on paper. Those securities can then end up in probate instead of passing under the trust’s terms, which is exactly the outcome most people create a trust to avoid.
Replacing a Lost or Destroyed Stock Certificate
If a physical stock certificate is lost or damaged beyond use, a medallion guarantee is part of the replacement process. You submit an affidavit of loss to the transfer agent, swearing the certificate is gone and agreeing to indemnify the company against future claims on the original.2SEC.gov. Exhibit 16(A)(1)(III) Lost Stock Affidavit The medallion guarantee on that affidavit confirms you are the rightful owner.
For higher-value certificates, transfer agents often require a surety bond on top of the affidavit and guarantee. The bond typically costs a small percentage of the certificate’s current market value and protects the issuing company if the original ever resurfaces in someone else’s hands.
When You Can Skip It
Not every securities transaction needs a medallion guarantee, and knowing the exceptions saves effort. Transfers between your own accounts at the same brokerage firm, where ownership does not change, generally do not require one. Routine electronic trades and rebalancing inside a single account skip the requirement entirely because the firm has already authenticated you through its own systems.
Many mutual fund companies waive the guarantee for redemptions below a certain dollar threshold or when proceeds are sent to a bank account already on file. The cutoff varies by institution. Rollovers from an employer-sponsored retirement plan to an IRA at another firm, where ownership stays the same, may also be exempt, though some custodians still ask for a guarantee. When you are unsure, call the receiving institution before you gather paperwork.
Why a Notary Stamp Will Not Work
People regularly confuse the two, and the difference matters because a notarized signature will not satisfy a transfer agent. A notary public verifies that you are who you claim to be and that you signed the document voluntarily. A medallion guarantee goes further: the institution confirms your identity, confirms you have the right to make the transaction, and then assumes financial liability if either is wrong.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities That liability is backed by a surety bond, which is why only specially authorized employees at participating institutions can apply the stamp.
If anyone at a bank or brokerage tells you to just get the document notarized, confirm the exact requirement in writing before you leave. Transfer agents routinely reject notarized documents when a guarantee was called for, and you end up back at square one.
Where to Get One
Start with the bank, credit union, or brokerage firm where you already hold an account. Most institutions provide medallion guarantees only to existing customers and will turn away walk-ins.1U.S. Securities and Exchange Commission. Medallion Signature Guarantees: Preventing the Unauthorized Transfer of Securities If your institution does not participate in one of the recognized medallion programs, it cannot provide the stamp regardless of how long you have banked there.
You have to appear in person. Bring a valid government-issued photo ID and the documents that need stamping. Depending on the transaction, you may also need recent account statements for the sending and receiving accounts, a death certificate and court appointment letters for estate transfers, or the trust instrument if you are retitling assets into a trust. Call ahead to confirm what the branch requires and whether an authorized signer is on site, because not every branch has one available at all times.
One more thing worth checking: each medallion stamp carries a coverage limit, and a stamp rated for a lower dollar amount cannot guarantee a higher-value transfer. If you are moving substantial holdings, ask the institution whether its stamp covers the transaction size before you make the trip. Many banks and brokerages provide the service free to existing customers; the real obstacle is almost always access rather than cost.